This blog discusses current weather, weather prediction, climate issues, and other topics

Tuesday, January 11, 2011

10:30 PM Nowcast

Based on the reports you have provided, right now there is roughly 1-2 inches over much of the area, with substantially more over Kitsap and SE of the Olympics and less near the Cascade foothills. As shown by the radar, precipitation is still occurring over much of the region:Well I hate to be a party pooper, but the warming is occurring aloft and the snow is fated to turn to rain. Here is the latest vertical sounding (10 PM) of temperature at Seattle. The temperature structure aloft is shown every hour (1206 is ten pm, time is in GMT)The temperature has warmed up considerably above 800 meters (around 2500 ft). You notice that the temperature is nearly constant in the lowest portion of the atmosphere..that is not a coincidence...it is very close to 32F all the way down since the precipitation is melting as it falls.

Here are the winds in the lowest 400o meters of the atmosphere from ten pm yesterday to 10 PM today. Strong southwesterly flow is found aloft (50 kts!) and the SW flow is moving down. SW flow is warm and moist.

You get the picture...this pretty snow is not going to last...it will turn to wet snow and then rain over the next 2-6 hours over most of the lowlands, depending where you are.

The other interesting story are the winds. There is a huge pressure difference the Cascades and some locations on the east side of the Sound and in the foothills are getting 40-50 mph gusts--like North Bend, Snoqualmie Ridge, and some locations near Enumclaw.

I don't know the most accurate way to measure precipitation of the frozen variety (do I just stick a ruler through the snow built up on my deck?) but it appears to be about 2-3" of accumulation here in the Phinney Greenwood area at the top of the ridge. Wondering if my kids' school will be cancelled in the morning or if the temps will warm and wash it all away.

Drove 15th Ave. NE between Shorline and Seattle at 9:00. About 1.5"-2" of accumulation. Between 175th and 125th saw three plows, one Shoreline plow coming off a minor arterial to hit 15th, WSDOT plowing 145th, and a SDOT plow on 15th. I suppose I should go walk the dogs and enjoy the snow while it is still here.

It's 2245 in Lower Queen Anne, calm and steady snow fall of small light flakes. My deck rail has almost 1" (not quite) of accumalation.It still seems cold out but could hear something dripping off the roof. It would be nice to see the pretty snow in the morning but I won't count on it.

3 miles NNE of Monroe @ 380' - Snow falling moderately, wind blowing from east. During the bigger gusts it starts looking like a white out. Near as I can tell there's about 1.5" of snow. Temp got as low as 29 but is now 30. Hope I wake up in the morning to lots of snow on the ground, but I recognize that's highly unlikely.

3 miles NNE of Monroe @ 380' - Snow falling moderately, wind blowing from east. During the bigger gusts it starts looking like a white out. Near as I can tell there's about 1.5" of snow. Temp got as low as 29 but is now 30. Hope I wake up in the morning to lots of snow on the ground, but I recognize that's highly unlikely.

11pm here in Portland and we are still @ 30* and steady freezing rain is still falling. If its not snow, its just not the same. Will be glad to see this gone tomorrow morning when I have to go to work in Vancouver.

Loving the "nowcasts" - we are at 4 inches of new snow in Bellingham. NWS says it stays snow here until 10 AM. Sounds different than what you are saying. Is that wrong or is it is Fraser outflow situation? Or what?

Several inches of snow in Bellingham since 8pm. Woohoo! I just got back from an invigorating ski through the neighborhood. Winter Storm Warning in effect until 7pm, changing to rain by 10pm. Finally, we got the best end of the snow stick!

Birch Bay: We left the house at about 7:00 - it was 34 degrees, 4.5" of snow, and still mixed precip coming down. It's melting fast where I work in the Cordata area of Bellingham. Roads are relatively good in both areas.

Woke up at 2:00am and through one calibrated eyeball.... I measured 5.1 inches on the top of my deck rail :)... It was still snowing hard, so I'd say we got 5-6 inches here overnight (sea level Hansville). Absolutely calm all night with no winds. Temperature is 39 right now and the wind is just starting to pick up. We just had a 25 mph gust. We have accumulated .36 of precip so far today. Current conditions @ www.SkunkBayWeather.com

Here in the Methow at 8am we've gotten 9 inches overnight. What I don't get is that it's snowing like mad but the radar images show that there's no precip. Precip shows in Seattle and Spokane but not here. What gives?

First big gusts hit the western shores of the Key Peninsula at about 4:00 am and its been gusty since then. The ~4 inches is now awful slush. Schools are closed here, too. 42 deg F. The rain gauge says 1.07 inches for last 24 hrs.

Just buy eyeing it from inside I'm guessing we may have actually gotten 3" in Ballard by about 3:30am (when I woke up briefly) although it may have just turned to rain about them because it was lightly raining.

I am sad that Snowpocalypse for today and tomorrow will not be happening ... possibly the only person I know over ten years old who feels that way.

For Mark in the Methow--you can find a coverage map, google for Spokane OTX 88d coverage blocking mountains or something like that. Here is one I see...http://www.nws.noaa.gov/oh/hrl/papers/2000mou/Jay/Fig30.gif

We ended up with about 6 inches here 5 miles ESE of North Bend. Wind was howling off and on during the night. Changed to rain at some point and the snow is sliding off our metal roof, but temp is still hovering around 30. Just the occasional breeze.

Temp last night was the same and we got snow, now it's rain. There's a lot about this weather stuff I just don't get, obviously :( Better read Cliff's book....got it for Christmas.....

Kids got a 2 hour delayed opening at school in Seattle. Better than nothing, like they said! They were so hoping for an epic storm....

Out here in Eatonville we started out as light snow around 6:30 pm....changed to sleet by 9:00 pm.....just rain by 10:00 pm. The winds really picked up overnight gusting to 48 mph at around 4:00 am. It's been a blustery, wet day out here all day. Like "dimension38" said...hoping to get a widespread 8 - 10 inches event that sticks around for a few days! Maybe later this month or in February? I think our chances get pretty slim after that.....Oh well! We can always hope for next year! Nuetral years are supposed to be almost as bad as La Nina years aren't they?

It's a bit late for a Nowcast, but I created a time-lapse video with annotated temperature of snow falling and then melting in University Park neighborhood (just north of UW):http://www.youtube.com/watch?v=7V8Kc7ExAPs